dicloxacillin

dicloxacillin
IUPAC name	(2S,5R,6R)-6-image = Dicloxacillin structure.svg | width = 200 | CAS_number = 3116-76-5 | ATC_prefix = J01 | ATC_suffix = CF01 | PubChem = 18381 | DrugBank = DB01211

dicloxacillin. It is a narrow-spectrum beta-lactam antibiotic of the penicillin class, specifically an isoxazolyl penicillin. It is primarily used to treat infections caused by penicillinase-producing Staphylococcus aureus, a mechanism of antibiotic resistance. The drug is typically administered orally for mild to moderate infections, such as those of the skin and skin structure.

Medical uses

Dicloxacillin is indicated for the treatment of infections caused by susceptible Gram-positive bacteria, most notably penicillinase-producing strains of Staphylococcus aureus. Common clinical applications include cellulitis, impetigo, and abscesses. It is not effective against infections caused by methicillin-resistant Staphylococcus aureus or most Gram-negative bacteria. Its use is often guided by antimicrobial susceptibility testing conducted in clinical microbiology laboratories.

Adverse effects

Common adverse effects are similar to other penicillins and can include gastrointestinal disturbances such as nausea, diarrhea, and vomiting. As with all beta-lactam antibiotics, there is a risk of hypersensitivity reactions, ranging from mild skin rashes to severe anaphylaxis. Use has been associated with cases of cholestatic jaundice and transient elevations in liver function tests. The Food and Drug Administration monitors reports of such adverse drug reactions.

Pharmacology

Dicloxacillin exerts its bactericidal effect by inhibiting the synthesis of the bacterial cell wall. It binds to specific penicillin-binding proteins located inside the cell wall of susceptible bacteria, disrupting the final step of peptidoglycan cross-linking. It is resistant to degradation by staphylococcal penicillinase due to the steric hindrance provided by its isoxazolyl side chain. The drug is acid-stable and is well absorbed from the gastrointestinal tract, with peak serum concentrations occurring approximately one hour after oral administration.

Chemistry

Dicloxacillin is a semisynthetic antibiotic derived from 6-aminopenicillanic acid. It is chemically designated as an isoxazolyl penicillin, characterized by a 3-(2,6-dichlorophenyl)-5-methyl-isoxazol-4-yl side chain attached to the beta-lactam core. This structure confers both stability against beta-lactamase enzymes and specificity for Gram-positive organisms. The compound is typically supplied as the sodium salt, a white to off-white crystalline powder that is freely soluble in water.

History

Dicloxacillin was developed in the 1960s by researchers at Beecham Research Laboratories as part of a broader effort to combat the rising prevalence of penicillinase-producing Staphylococcus aureus. This period saw the introduction of several penicillinase-resistant penicillins, including methicillin, oxacillin, and nafcillin. The work built upon the foundational discoveries of Alexander Fleming and the mass-production techniques pioneered by Howard Florey and Ernst Chain. Its approval by the Food and Drug Administration followed extensive clinical trials.

Society and culture

Dicloxacillin is available as a generic medication in many countries, marketed under various brand names. Its role in therapy has been partly supplanted by other anti-staphylococcal penicillins and broader-spectrum agents, but it remains a listed essential medicine in some national formularies. The ongoing challenge of antimicrobial resistance, particularly the global spread of MRSA, influences its contemporary use. The World Health Organization includes related antibiotics in its Model List of Essential Medicines.

Category:Penicillin antibiotics Category:Isoxazoles Category:World Health Organization essential medicines